Wireless networks are becoming ubiquitous, and the density of wireless networks is increasing. For example, in enterprise and campus settings, high density (HD) wireless local area networks (HD-WLAN) with access point distances of 10-20 meters will soon become common. In such networks, interference is the deciding factor in determining the network-wide throughput performance. Tuning of certain medium access control (MAC) parameters may have an effect on the performance of individual access points as well as network-wide throughput. For example, the clear channel assessment (CCA) threshold may have an effect on network-wide throughput.
Typical CCA mechanisms include sampling the net radio frequency (RF) energy on a channel and comparing it to a threshold prior to initiating channel access. A network node (e.g., access point or mobile station) initiates channel access only if the sampled RF energy is lower than the CCA threshold. The value of the CCA threshold can have a significant impact on network performance. If set too high, the network node may transmit when it should not (e.g., the node's transmissions lead to unacceptable added interference with ongoing transmissions, degrading the aggregate throughput). If the CCA threshold is set too low, a network node may pass up opportunities to transmit when it could have without interfering with others, thereby again degrading network performance.